This invention relates to an improved method for coating carpets and other fabrics with fluorochemicals.
The term "carpet" as used herein means fabric comprising pile fibers attached to a primary backing.
Fluorochemicals are conventionally used in the carpet industry by carpet manufacturers and fiber producers to improve the soil-resistance of their carpets. The fluorochemical when present as a coating on the carpet improves the soil-resistant characteristics (e.g. soil shedding, oil and water repellency) of the carpet. In commercial practice by carpet manufacturers, fluorochemical is typically applied to dyed carpet by passing the carpet in a horizontal direction face up under nozzles which spray a determined amount of aqueous fluorochemical emulsion onto the carpet pile fibers. The carpet is then dried, for example, for 1 to 2 minutes in a 121.degree. C. oven, to remove the water and leave the fluorochemical on the carpet as a coating. Normally, a sufficient amount of the fluorochemical is applied to the carpet so that the coating contains from 200 to 800 ppm fluorine based on the weight carpet fiber (o.w.f.).
This spray method of coating carpets with fluorochemical has the disadvantage that the fluorochemical does not penetrate down into the carpet fabric and therefore does not provide optimum soil protection.